IS 4318 : 1993 Solid core porcelain insulators for overhead traction lines

1 Scope

This standard covers the requirements and method of tests forsolid core porcelain insulators, both standard and for pollutedzones, used on single phase electric traction lines having anominal voltage of 25 kV (line-earth) ac at 50 Hz. The maximumsystem voltage may, however, go up to 27.5 kV.

2 Reference

List of Referred Indian Standards

IS 1367 : Part 16 :1979 Technical supply conditions for threaded steelfasteners:Part 16 Designation system and symbols

IS 1885 : Part 54 :1980 Electrotechnical vocabulary :Part 54 Insulators

IS2071 Methods of high voltage testing:

Part 1 :1974General definitions and test requirements

Part 2 :1974Test procedures

Part 3 :1976Measuring devices

IS 2108 :1977Blackheart malleable iron castings

IS 2629 :1985Recommended practice for hot-dip galvanising oniron and steel

IS 2633 :1986Methods for testing uniformity of coating of zinc coated articles

IS4218ISO metric screw threads :

Part 1 :1976Basic and design profiles

Part 2 :1976Diameter pitch combinations

Part 3 :1976Basic dimensions for design profiles

Part 4 :1976Tolerancing system

Part 5 :1979Tolerances

Part 6 :1978Limits of sizes for commercial bolts and nuts(diameter range 1 to 52 mm)

IS 4759 :1984Hot-dip zinc coatings on structural steel and other allied products

IS 5517 :1978Steels for hardening and tempering

IS 6745 :1972Method for determination of mass of zinccoating on zinc coated iron and steel articles

IS 8349 :1977Deviations for untoleranced dimensions of malleable iron castings

IS 8704 :1978Methods for artificial pollution test on highvoltage insulators for use on ac system

IS 8765 :1978Ceramic insulating materials for electrical purposes

IS 13134 :1992Guide for the selection of insulators inrespect of pollution conditions

IS 13305 :1992Permissible limits of visual defects for insulating porcelains for electrical circuits